# 变量的创建：买苹果
price = 10.5
weight = 7.5
money = price * weight
print("苹果是 %.1f 元" %money)

# 变量的修改
year = 2024
print(year)
year = 2025
print(year)

cash = "10元"
cash = 10
print(cash)

# type
a = "123a"
print(type(a))  # <class 'str'>

# isinstance
a = "123a"
print(isinstance(a, int))  # False